1. Prior Art
Rohn et. al., in U.S. Pat. No. 3,247,516 issued Apr. 19, 1966, describe a microwave reflector that is mounted on a tripodal tower using angled iron.
Weir, in U.S. Pat. No. 4,490,726 issued Dec. 25, 1984, describes a collapsible roof top microwave antenna with a wind loading feature.
Edwards, in U.S. Pat. No. 4,565,346 issued Jan. 21, 1986, describes an adjustable bracket mount for a satellite dish antenna.
2. Background
The present invention relates to an apparatus for supporting a sending or receiving device on a tripodal tower.
New installations of satellite dish antennas for television are controlled by local regulations, and depending on the jurisdiction may be installed at a maximum height, for example, of fifteen feet. Usually this installation is made atop a single fifteen foot section of four inch or six inch hot rolled tubing, or a squared version of such tubing. The local regulations are based on safety requirements which seem to indicate that installation higher than fifteen feet using such materials is unsafe. Because houses and trees are often higher than fifteen feet and block microwave and other signals, the fifteen foot height limitation makes it necessary for the television owner to install the dish antenna on top of the nearest hill, or alternatively, to install the antenna in a large flat open area with no obstructions, and run great lengths of cable from the antenna to his television. In highly populated areas there are a great many more man made obstructions, and disputes over easements may make installation of the antenna large distances from the television impractical.
Although a new installation cannot be made higher than fifteen feet, there are few regulations relating to the installation of dish antennae on existing structures such as a roof on a high rise building, if adequately supported, or an existing television antenna tower. Many jurisdictions have regulations against installing dish antennas on house roofs.
The difficulty and the resulting expense of providing adequate support on a roof or other high structure which is not otherwise suitable for supporting a dish antenna renders the use of such structures, in most cases, impractical.
Existing television towers, especially those of the tripodal type, having three legs, which are connected to each other by connecting braces, firmly implanted in the ground, in from three to six feet of concrete, depending on the height of the tower, have great structural strength. Because no alteration of the tower need be made, if a means could be provided, that is not too complicated or expensive to install, for supporting a dish antenna on an existing television tower, all the problems delineated above could be avoided.
It has been found that the problem with installing a dish antenna on an existing television tower is that such antennas have large wind resistance, and depending on the directional requirements of the antenna, and the direction of the wind, the wind resistance of the antenna may cause severe twisting forces, or a torque to be exerted on the tower by the antenna, and although a tripodal television tower is structurally strong, if strong forces are exerted on such a tower unevenly at one point, the tower could crumble. Also, the support means used for holding the dish antenna on the tower must be strong enough to withstand such forces and must be attached to the tower in a manner that prevents its separation from the tower when such forces are present.
Accordingly, there is a need in the art for a low cost, easily installed apparatus having sufficient strength to support a dish antenna on a tripodal tower, and a means for converting twisting and torque forces exerted by the apparatus on the tower into harmless up or down forces which can be easily handled by the tower.